Search Results (241)

With the increasing demand for sustainable animal production, the utilization of agricultural and processing by-products as functional feed ingredients has gained growing attention. However, the application of Xiasangju processing residues, a by-product generated during the industrial processing of the traditional Chinese herbal formula Xiasangju, in poultry nutrition remains poorly understood. This study aimed to evaluate the nutritional composition, bioactive components, and potential functional effects of Xiasangju processing by-products as a dietary supplement for late-laying hens. Chemical composition was characterized using LC-MS and conventional nutritional analysis, while potential anti-inflammatory mechanisms were predicted via network pharmacology. A total of 288 Jingfen laying hens (55 weeks old) were randomly assigned to four dietary treatments supplemented with 0, 0.5%, 1.0%, or 1.5% Xiasangju processing by-products for 56 days. Results showed that 11 major active compounds were identified, including relatively high levels of linarin and rosmarinic acid, along with abundant crude protein, fiber, minerals, and amino acids. Dietary supplementation at 1.5% was associated with higher egg production rate, egg weight, and yolk color without obvious adverse effects on organ indices or serum biochemical parameters. This treatment was also associated with lower inflammatory gene expression, including IL-6 and COX-2 in the ileum and NF-κB, IL-6, COX-2, and TNF-α in the cecum. No significant effects were observed on antioxidant status in yolk or liver, or intestinal morphology. Integrated analyses using network pharmacology, molecular docking, and in vitro COX-2 inhibition suggested that anti-inflammatory-related responses may involve COX-2-related pathways, while 16S rRNA sequencing indicated changes in gut microbiota composition. In conclusion, Xiasangju processing by-products may serve as a potential functional feed ingredient for late-laying hens, with 1.5% inclusion showing favorable overall performance under the conditions of this study. These effects may be associated with the combined contribution of residual nutrients and bioactive compounds in the residues. Full article

Enzymes have the potential to enhance nutrient utilisation and provide economic and environmental benefits in reduced protein (RP) diets; however, responses to different inclusion levels of phytase and carbohydrase enzymes remain inconsistent. Therefore, the present study aimed to evaluate the effects of phytase, xylanase, and β-glucanase inclusion levels in RP diets on nutrient digestibility and performance in laying hens. A total of 8 dietary treatments were allocated to 13 replicate cages of two hens per cage per treatment (n = 208) from 35 to 57 weeks of age. Experimental diets comprised two protein levels (standard protein (SP) at 16.5% crude protein versus RP at 14.5% crude protein), two phytase levels (600 and 1200 FTU/kg), and two XB levels (xylanase, β-glucanase 100 g/ton and 150 g/ton) were examined via a 2 × 2 × 2 factorial design. Between 35 and 57 weeks of age, no significant interactions were observed in laying performance parameters. However, RP diets significantly decreased egg weight across all periods, 35–47 weeks (p = 0.049), 48–57 weeks (p = 0.045), and overall, from 35 to 57 weeks (p = 0.044). Reduced protein diets also decreased egg mass from 35 to 47 weeks (p = 0.035). High Xylanase and β-glucanase (XB) inclusion (150 g/ton) lowered hen day egg production during 48–57 weeks (p = 0.015). At 47 weeks, RP diets reduced yolk weight (p = 0.021) and increased egg shape index (p = 0.048). Additionally, XB at 150 g/ton with 600 FTU/kg PhyG improved shell breaking strength (p = 0.046) but reduced it at 1200 FTU/kg. At 57 weeks, RP diets decreased albumen weight (p = 0.016), albumen proportion (p = 0.006) and increased yolk proportion (p = 0.005). Xylanase and β-glucanase inclusion at 150 g/ton reduced shell breaking strength (p = 0.036), and XB reduced yolk colour score (p = 0.038) only in SP diets. Also, RP diets reduced excreta moisture (p = 0.015) and improved dry matter digestibility (p = 0.020). Notably, feeding RP diets increased apparent metabolisable energy digestibility (p = 0.003), decreased protein excretion (p < 0.001) and increased apparent protein digestibility (p = 0.013). It is therefore concluded that decreasing RP diets to appropriate levels may benefit the environment without affecting the feed efficiency of laying hens. Full article

Porcine epidemic diarrhea (PED), caused by the PED virus (PEDV), remains one of the most devastating diseases in the swine industry, with a mortality rate approaching 90–100% in suckling piglets due to severe dehydration and electrolyte imbalances. Passive immunization with egg yolk antibodies (IgY) represents a promising therapeutic strategy. In this study, we developed a novel recombinant adenovirus, rADM-IFN-G-ped, co-expressing selected antigenic regions of the PEDV S protein and chicken interferon-gamma (ChIFN-γ) as a molecular adjuvant. Laying hens were immunized with this construct to produce PEDV-specific IgY, which was subsequently purified from eggs using a polyethylene glycol (PEG-6000) precipitation method. The induced IgY demonstrated potent neutralizing activity against PEDV in vitro, with a neutralization titer (NT₅₀) of 1:96, which was significantly higher than that of IgY derived from hens immunized with a commercial inactivated PEDV G2b vaccine (NT₅₀ = 1:52). In a passive immunization and challenge trial, piglets treated with the rADM-IFN-G-ped-derived IgY exhibited significantly reduced fecal viral RNA shedding following challenge with the virulent PEDV-NX-2022 strain, compared to control groups. Crucially, while all piglets in the challenge control group succumbed to infection within 72 h, a 50% survival rate was achieved in the IgY-treated group. Histopathological examination of intestinal tissues further confirmed the protective efficacy, showing that IgY treatment markedly alleviated villous atrophy, epithelial necrosis, and inflammatory cell infiltration in the small intestine. These findings demonstrate that vaccination of laying hens with the rADM-IFN-G-ped recombinant adenovirus elicits a robust immune response, enabling the production of protective IgY. This proof-of-concept study establishes the viability of the multi-epitope adenoviral IgY platform as a passive immunization strategy against PEDV. Full article

Background: The translocation of diet-derived antigens from the maternal intestine to breast milk represents a primary gateway for neonatal immune priming, yet the structural basis for why certain proteins survive this transit while others do not remains poorly understood. This review introduces the “Survivor Peptide” hypothesis, proposing that specific food allergens possess intrinsic “stability architectures” that enable them to resist maternal digestion and navigate the gut–mammary axis to reach the infant in an immunologically active form. Methods: We analyzed the current literature regarding the detection and structural characteristics of food allergens in human milk. Integrating evidence from 26 major sources, we performed an in silico structural analysis of five representative “survivor” proteins: Gal d 1 (egg white), Bos d 5 (cow’s milk), Gal d 6 (egg yolk), Tri a 19 (wheat), and tropomyosin (Der p 10-mite/shellfish). High-resolution 3D models were retrieved from the Protein Data Bank and AlphaFold2, and then visualized in UCSF ChimeraX to map stability anchors, including disulfide bonds and hydrophobic clusters, against solvent-accessible IgE-binding epitopes. Results: We identified and categorized allergens into distinct Molecular Resilience Architectures: the “Covalent Cage” (Gal d 1), defined by dense disulfide stapling, the “Glycoprotein Shield” (Gal d 6), utilizing yolk-matrix structural anchors, the “Topological Shield” (Bos d 5), characterized by a stable β-barrel, and “Coiled-Coil Rigidity” (Der p 10). These frameworks protect large, immunogenic fragments that maintain the spatial arrangement required for IgE cross-linking. Conclusions: Allergen persistence in the gut–mammary axis is dictated by a protein’s intrinsic structural architecture. Identifying these stability fingerprints provides a unified theory for allergen persistence and offers a path for refining component-resolved diagnostics and neonatal oral tolerance strategies. Full article

This study evaluated the effects of arginine (Arg), guanidinoacetic acid (GAA), and citrulline (Cit) supplementation in reduced protein (RP) diets on the production performance, serum uric acid level and bone quality of aged laying hens. A total of 208 Hy-Line Brown laying hens from 60 to 75 weeks of age were assigned to eight dietary treatments, with 13 replicate cages per treatment and two hens per cage. Experimental diets comprised two protein levels (standard protein at 15.8% crude protein versus RP at 13.8% crude protein), and six RP diets supplemented with two inclusion levels (0.06% and 0.12%) of Arg, GAA, or Cit. Overall, increasing Cit supplementation improved productive performance compared with Arg and GAA, particularly by increasing egg weight (p = 0.048), egg mass (p = 0.019), and feed intake (p = 0.014) over the entire experimental period. In addition, Cit increased egg weight during 60–67 weeks (p = 0.049) and improved egg mass during 68–75 weeks (p = 0.014). Furthermore, supplementation of 0.12% Cit in RP diets significantly increased feed intake compared with standard protein (SP) and RP diets from 60 to 67 weeks (p < 0.001; one-way ANOVA). Both Cit and Arg supplementation increased yolk weight compared to GAA (p = 0.018). Further, Arg supplementation to the RP diet at 0.06% significantly increased energy digestibility compared to the SP and RP diets (p = 0.037). Increasing Arg and GAA levels reduced bone breaking strength compared with their respective low levels, whereas increasing Cit level enhanced tibia (p = 0.014) and femur (p = 0.006) bone breaking strength. Low-level GAA supplementation also increased tibia breaking strength. Thus, a moderate reduction in dietary protein level by two percentage points, combined with Cit supplementation at the high level (0.12%), was effective in enhancing egg mass, egg weight, yolk weight, and bone breaking strength in aged laying hens. These findings suggest that RP feeding strategies supplemented with functional Arg precursors may support productive efficiency, skeletal health, and nutrient utilization in late-lay hens. Full article

This study evaluated how two commercial egg types (free-range and barn-laid) influence the physical, compositional, and rheological properties of egg white and yolk in raw and grilled states. Free-range eggs showed stronger correlations between external dimensions and internal composition, suggesting potential for nondestructive grading, whereas barn eggs exhibited heavier shells but weaker morphometric–composition relationships. Haugh units differentiated production systems, and yolk redness was the only color parameter clearly associated with free-range origin. Mechanical tests revealed that barn eggs had shells capable of absorbing more energy during rupture. Rheological measurements showed matrix-dependent behaviors: in raw samples, egg white behaved as a weakly structured viscoelastic fluid, while yolk exhibited characteristics of a concentrated lipoprotein emulsion. Stress, frequency, and temperature sweeps revealed contrasting behaviors between the two commercial egg types: barn-laid eggs displayed a stronger egg-white protein network, whereas free-range eggs showed a more reinforced yolk lipoprotein matrix under the conditions evaluated. Yolk behavior fitted the weak gel model with excellent accuracy (R² ≈ 1), while egg white did not. Steady shear and three-step tests confirmed pronounced shear thinning and thixotropic behavior in both matrices, with barn eggs showing higher viscosities but lower structural recovery. Thermal treatment reduced the strong rheological differences between raw egg white and yolk, yet production system effects persisted. All grilled samples behaved as weak gels, with barn egg whites forming stiffer networks and free-range yolks generating more elastic, cohesive, and energy-absorbing gels. A trend toward higher MUFA levels was observed in raw free-range yolks. Microscopy further clarified how production system shapes the structural and functional behavior of egg matrices. Full article

Caviar extract is widely used in luxury cosmetics and is generally defined as a homogeneous ingredient derived exclusively from sturgeon eggs. However, its molecular composition remains inadequately characterised. In this study, proteomic analyses were performed on 14 commercial caviar samples from different sturgeon species and geographical origins, examined independently in two laboratories. Across three single-origin samples (Germany, Poland, China), 1437 protein groups and 3452 unique peptides were identified, with consistent overlaps with sturgeon ovarian fluid (≥25–38 proteins). Extending this analysis across multiple species confirmed the presence of ovarian fluid-associated proteins in all examined groups, including 69 in Acipenser baerii, 61 in A. gueldenstaedtii, 55 in A. schrenckii, and 49 in H. huso. The results showed that ovarian fluid is consistently co-extracted during standard roe harvesting processes due to its strong egg surface adhesion, making this co-extraction intrinsic rather than incidental. Proteomic profiling revealed a complex mixture of egg- and ovarian fluid-derived proteins, including zona pellucida glycoproteins, immunoglobulins, complement components, proteases, coagulation factors, and antioxidant enzymes. Many of these proteins influence skin biology, suggesting that the functional effects attributed to caviar extract may partially originate from ovarian fluid constituents rather than yolk-derived nutrients alone. At the same time, the presence of immune-active and enzymatic proteins raises important questions regarding safety assessment and regulatory oversight. Species-specific proteomic clustering also indicates considerable composition heterogeneity, challenging assumptions of ingredient standardisation. Together, these results highlight a discrepancy between current definitions and the molecular reality and underscore the need for improved molecular characterisation, updated regulatory definitions, and the consideration of alternative, cell-based production strategies for cosmetic applications. Full article

The aim of this study was to investigate the substitution of egg yolk in mayonnaise-type sauces with alternative protein components and to optimize the hydrocolloid composition for improved stability and rheological properties. Mustard powder (1%), soybean flour (1%), casein (2%), and cream powder (1%) blends were employed as emulsifiers. The influence of the ratio of potato starch, carboxymethylcellulose (CMC), pectin, and xanthan gum (0–1% each) on the properties of low-fat mayonnaise formulations with 30% oil content was examined. Sedimentation and thermal stability tests revealed high resistance of all samples (98–99%) after 24 h of storage. Optical microscopy confirmed a homogeneous structure with individual dispersed particles of 100–150 μm corresponding to plant protein inclusions. The particle size distribution D [3,4] exhibited a bimodal profile with peaks at 0.1–1 μm and 2–8 μm, indicating efficient homogenization. Storage experiments demonstrated an increase in particle size by 1.4–1.6 times and a decrease in viscosity, likely due to flocculation and aggregation of polysaccharide clusters into larger agglomerates. Among the tested formulations, the sample containing 0.3% CMC, 0.3% xanthan gum, and 0.4% pectin showed the most favorable physicochemical and sensory properties, highlighting the synergistic effect of hydrocolloid blends in stabilizing reduced-fat mayonnaise-type emulsions. Full article

This study aimed to determine the effects of incorporating probiotic fermented natural lactic acid bacteria (PFJ) into the drinking water of laying quails subjected to temperature stress on egg production, egg quality, cecum microbiology, blood parameters, and incubation performance. A total of 260 Japanese quails (Coturnixcoturnix japonica) aged 8 weeks were used, of which 200 were females, and 60 were males. The quails were divided into four groups, each containing 50 individuals, and further split into five subgroups of 10 quails. For every 10 female quails, three male quails were housed together in cages. The experiment was conducted under normal environmental conditions in control, PFJ, heat-stressed control, and heat-stressed PFJ groups. Temperature stress (34–36 °C) was applied for 8 h daily. The results indicated that by the end of weeks 1–4, the feed conversion ratios of all groups were significantly different, with the best feed conversion ratio of 2.36 found in the PFJ group under temperature stress. Throughout the periods of weeks 1–4 and 5–8, there were statistically significant differences (p < 0.01) in the daily average feed consumption and egg weights among all treated groups. Temperature stress and the addition of PFJ significantly affected shell thickness, Haugh units, albumen weight, yolk weight, and yolk color; no significant impacts were observed on egg shape index, yolk percentage (%), albumen percentage (%), and specific gravity (g/cm³). The highest counts of lactic acid bacteria (LAB) were found in the PFJ-treated groups under both normal and temperature-stressed conditions. Under temperature stress, the levels of Enterobacter, coliform, and E. coli decreased with the addition of PFJ. Regarding blood parameters, significant differences (p < 0.05) were observed in total protein values among groups, while differences in chloride, triglycerides, total cholesterol, LDL cholesterol, HDL cholesterol, and triglyceride concentrations were not statistically significant (p > 0.05). Furthermore, the addition of temperature stress and PFJ significantly affected fertility rates, incubation efficiency, and hatchability. In conclusion, these findings suggest that PFJ could be considered a potential probiotic alternative for improving nutrition in laying quails under conditions of temperature stress. Full article

Microbial proteases are fundamental towards the eco-sustainability of proteolysis at the industrial scale. A proteolytic broth was obtained from a bioreactor fermentation of a proteolytic Bacillus strain isolated from an industrial alkaline bath. Broth proteolytic activity was applied to leather tanning and to the removal of protein stains. The hide tanned with the microbial proteolytic fermentation broth showed better physical properties than the one tanned with commercial pancreatic proteases of the same activity (780 LVU). Proteinaceous stains on cotton fabric were removed more efficiently using the Bacillus proteolytic broth than water or a commercial detergent. Blood and egg yolk disappeared in less than 30 min. The removal of soya and English sauce stains was even faster. Broth proteolytic activity was characterised by caseinolytic (5200 LVU), collagenolytic (10.0 U mg⁻¹), elastolytic (3.7 U mg⁻¹), and keratinolytic (0.7 U mg⁻¹) activities, which were compared with those of a commonly used commercial protease. Alkaline protease activity in the broth was demonstrated by a 20% increase in caseinolytic activity from pH 5 to 8. Besides the demonstrated applications in the leather and detergent industries, the produced alkaline microbial proteases can also be used in the treatment of proteinaceous wastes and effluents, offering potential environmental benefits reinforcing and impacting the bioeconomy. Full article

Background: Presence of milk, fruits, eggs, fish, nuts and wheat antigens in the amniotic fluid is described in the literature. Studies show a contradictory relationship between maternal exposure to allergens and early sensitization of the fetus to allergens. Hemochorionic type of the human placenta allows for easier transfer of nutrients and antibodies from the mother’s blood to the fetal circulation through the direct contact of maternal blood with the fetal chorion. During the third trimester of pregnancy, immunoglobulin G (IgG) is actively transferred through the placenta into the fetal via neonatal FcRN receptor (FcRN). In addition, monomeric immunoglobulin E (IgE) cannot cross the placenta Aim: The objective of our study is to track intrauterine sensitization to essential food proteins at birth in umbilical cord blood in mothers with established peripheral blood eosinophilia and in their infants using allergen-specific IgE and IgG. Methods: An observational study was carried out in a cohort of 22 mothers with eosinophilia and their babies. Differences in expression between groups were assessed. Blood samples were collected to determine serum IgE and IgG specific to a set of inhalant and food allergens. Results: We did not find a significant correlation between specific IgE to cow’s milk (p = 0.857), egg white (p = 0.926) and egg yolk (p = 0.096) in umbilical cord blood and maternal blood samples taken immediately before birth. Spearman’s correlation of the specific IgE and IgG in umbilical cord blood showed no dependence between the two variables. In contrast, statistical analysis showed that maternal eosinophilia in peripheral blood could be a risk factor for the development of allergy in the offspring (χ², p = 0.0347). However, given the small number of patients, this claim needs to be confirmed with further studies. Conclusions: Due to the functional immaturity of the developing immune system of the fetus, the generation and maintenance of an independent immune response to allergens are incomplete. Maternal IgG (specific) passes to the baby and high maternal IG to a specific allergen reduces babies IgE production. In addition, low maternal specific IgG may promote IgE production in the baby under the influence of microenvironmental factors (cytokine background). The main limitation of our study is the small number of patients. Further research is needed in this direction to clarify the mechanisms and risk factors for early sensitization in newborns. Full article

The conventional method for detecting protein content in egg albumen is the Kjeldahl method, but this method cannot be applied in practical production due to cost limitations. Therefore, we developed albumen density (AD), which had certain potential application value in low-cost and efficient evaluation of albumen protein content. We calculated the heritability of AD in White Leghorn (WL) chickens and its correlation with average albumen protein quantity (AAP), total albumen protein quantity (TAP), albumen weight (AW), albumen volume (AV), egg weight (EW), albumen height (AH), haugh unit (HU), and yolk color (YC). It is worth noting that albumen protein content was measured in a small subset of samples. The average value of AD in eggs was 0.97 and its heritability was less than 0.1. The average value of AAP in eggs was 10.1%, and the average value of TAP in eggs was 2.95 g. There were significant positive correlations between AAP, TAP, AW, AV, AD, and EW, and there were strong positive genetic and phenotypic correlations between EW, AW, AV, and AD. The results of this study indicated that AD might have potential value as a supplementary tool for albumen protein trait selection in breeding. Full article

Due to global increases in poultry meat and egg production, consumers request sustainable agricultural practices, requiring alternative solutions for future feeding. Global egg production increased by over 41% between 2000 and 2020, from 51 to 87 million tonnes, at an average increasing rate of 3%. Similarly, the production of poultry meat reached 145 million tonnes in 2023 and continues to increase, which amplifies the pressure on sustainable alternative feed solutions. Commercial poultry diets are typically based on a cereal (corn or wheat) as an energy source and a quality protein source, especially soybean meal (SBM), to provide essential amino acids. Soybean production is associated with deforesting and land use in several countries, sensitiveness to supply chains and price volatility. As a response to these challenges over the last decade, research and commercial innovation have intensively focused on alternative and novel feed resources that can be integrated into both broiler and layer diets. Some future candidate ingredients are insect meal, algae, agro-industrial by-products such as distiller’s dried grains with solubles (DDGS), brewery spent grains (BSG) and fermented feedstuffs (oilseed cakes/meals). Literature data showed that moderate inclusion of these alternative ingredients can be partly integrated in poultry diets, without compromising egg or meat quality. In some cases, studies showed improvements of productive performances and specific quality traits (yolk color, fatty acids and antioxidant compounds), offering potential to valorize waste streams, improve local circularity and provide functional ingredients for animals and humans. However, challenges still remain, especially in terms of nutrient variability, digestibility limitations, higher processing costs and still-evolving regulations which constrain mainstream adoption of some of these potential future alternatives. Full article

The egg industry continues to search for alternative feed ingredients that support production efficiency, enhance egg quality, and add nutritional value. Microalgae are rich in protein, pigments, and long-chain polyunsaturated fatty acids, making them promising candidates for poultry diets. This study evaluated the effects of dietary inclusion (1 and 2%) of four microalgae species, Arthrospira platensis (Spirulina), Hydrodictyon sp., Uronema sp., and Vaucheria sp., on laying hen performance, egg quality, yolk fatty acid composition, and bone strength. Seventy-six Lohmann LSL-Lite hens (92 weeks of age) were randomly assigned to nine treatments (control diet or one of eight microalgae diets). Feed intake, egg production, egg mass, feed conversion ratio, eggshell traits, yolk color, yolk fatty acids, and tibial breaking strength were measured. Inclusion of microalgae did not negatively affect hen performance, egg quality, nor bone strength. Spirulina significantly improved egg production and egg mass (p < 0.05). Increasing levels of Spirulina, Hydrodictyon sp., and Uronema sp. enhanced yolk color (all p < 0.05), while Vaucheria sp. showed no effect (p > 0.05). Yolk fatty acid profiles were only modestly altered, with increased docosahexaenoic acid observed in hens fed Hydrodictyon and Uronema (p < 0.05). In conclusion, low-level dietary inclusion of these microalgae species appears safe for laying hens and may provide added value through improved yolk pigmentation and modest omega-3 enrichment. Full article

Egg quality is a critical economic trait in poultry production, influencing consumer preference and production efficiency. The genetic and epigenetic regulation of egg quality involves complex biological pathways across various traits such as shell quality, albumen composition, and yolk biochemistry. This review synthesizes recent advances in the genetic, molecular, and epigenetic mechanisms that determine poultry egg quality. Specifically, it focuses on external traits such as eggshell strength, color, and thickness, and internal traits including albumen height, yolk composition, and the Haugh unit. Through genome-wide association studies (GWAS), quantitative trait loci (QTL) mapping, whole-genome sequencing (WGS), and multi-omics approaches, key candidate genes such as OC-116, CALB1, CA2 (shell formation), OVAL, SPINK5, SERPINB14 (albumen quality), and FGF9, PIAS1, NOX5 (lipid metabolism) have been identified. These genes play a pivotal role in shell biomineralization, albumen protein regulation, and yolk lipid transport. This review also explores the heritability of these traits, emphasizing the challenges posed by polygenic architecture and the influence of environmental factors. Furthermore, it addresses the dynamic spatiotemporal regulation of egg quality traits, including epigenetic layers such as DNA methylation, histone modifications, RNA methylation, and post-translational protein modifications. This paper highlights the application of these findings to breeding programs via genomic selection, marker-assisted breeding, and epigenetic engineering approaches. Future directions for precision breeding and the development of functional eggs with enhanced quality are also discussed. Full article